Improvement in steam-generators



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UNITED STATES PATENT OEEICE.

GEORGE I. WASHBURN, OF IWORCESTER, MASSACHUSETTS.

IMPROVEMENT IN STEAM-GENERATORS.

Specification forming part of Letters Patent No. 49,810, dated September 5, 1865.

T0 all whom it may concern Beit known that I, GEORGE I. WAsHBUEN, of the city and county of Worcester, and State of Massachusetts, have made new and useful Improvements in Steam-Boilers and Utilizing the Heat of the Furnace; and I do hereby declare the following to be a clear'and exact description of the same, reference being had to the accompanying drawings, which are made part of this specification, and in which my improvements are represented by two vertical sectional views.

Iconstruct a furnace capable of withstanding greatinternal pressure, within which I place the fuel, forcing in air to maintain the combustion of the fuel. I cause the volatile products of combustion, together with all the dirt, dust, or other matters which may pass out of the furnace with these gases, to pass through a separate chamber, made of equal strength with the furnace, and WhichI term the cleanser, and during the passage through this cleanser all these extraneous matters which would be injurious to the machinery, are removed from the gases by the action of water-spray or other device and retained in the cleanser, from which they are removed from time to time, as desirable. Ialso generate steam within this furnace either by means of a boiler, which may be a convoluted pipe or a vessel of suitable form, or by injecting water into the furnace, dispensing with a boiler; or I may inject air into the furnace-space above the re for the purpose of utilizing the heat by its expansion ot' the said air.

The heated and cleansed gases are conveyed fromthecleansertoanysuitableenginethrough a passage controlled by a stop cock or valve, by means of which any desired pressure may be maintained in the furnace.

In case I use a steam-boiler, as it is located within this furnace, and is under an external pressure through the means of the valve K, which is within control, the strength required in the boiler will be only that requisite to withstand the difference between the internal and external pressure. As this difference may be reduced at will to any extent, the thickness ot' the boiler may be reduced to its minimum, and be determined by other considerations than its power of resisting pressure. The consequence of this comparative thinness is that the transh mission of heat from the furnace to the contained water is greatly facilitated. Another consequence is that I can use highly-conducting and comparatively unoxidizable materialsuch as copper-for the boiler, which would not be practicable under other circumstances, owing to its inferior tensile strength when heated.

The form of boiler which I prefer is shown in Figure l, where the convoluted pipe B, which contains a small quantity of water, serves as a generator ot' steam, and may be considered as an instantaneous generator.

A is the furnace, with walls A of any requisite thickness and strength. O are the gratebars, and A the ash-pit. The air is forced in to supportl combustion through the pipe H, and B is the inclosed boiler, suspended from the root' of the furnace and communicating by steanrpipe G with the engine. The supplypipe G, which is a continuation of the boiler B, is connected with a suitable force-pump.

The heated gases and volatile products of combustion, together with all the dirt, dust, and other matters which may pass out of the furnace with these gases, are carried by pipe I) into the cleanser E, and the gases, havingbeen separated from the dirtfeither by being passed beneath the surface of the water, as in Fig. l, or through a porous diaphragm, as in Fig. 2, proceed through pipe T to the engine.

The pipe T and steam-pipe O are controlled by valves K and W, respectively, by means of which the pressure in the boiler and in the furnace is controlled at will.

Fig. 2 represents a base-burning furnace, whosewallsformapartoforareentirelyinclosed within the strong walls A', Fig. l, of the chamber A above spoken of. The usual advantages are derived from the use of this kind of fur* nace, and the volatile results of combustion are conveyed bya pipe through the inclosing chamber B into the cleanser, in which they are separated from their accompanying dirt, dust,-

tc., by passing through the porous diaphragms Q, which may be wet or dry and of any effect ive construction.

The chamber Af, which surrounds the basen l i l i pipe V. This heated fluid, Whatever it may be, is added to or used separately from the heated product of combustion above spoken of.

Whatever heat may be imparted to the contents of the cleanser by the heated gases Which vpass through it is utilized in the engine by means of the steam caused thereby.

In some cases I dispense with the cleanser and retain the pressure in the furnace for the sake of the thin boiler. I then locate a backpressure or suitable safety-valve in the pipe D, for thepurpose of maintaining the requisite pressure Within the furnace A. In such cases I may inject into the boiler water, gases, or air, to be expanded by the heat of the furnace acting through the thin boiler and used as a motive power.

The products of combustion and the eX- panded contents of the boiler B may be conducted to different engines.

The heat which radiates from the outside of the furnace may be utilized byawaterg'acket.

The boiler may be dispensed with and all the stein that is used be generated in the cleanser The consumption of the fuel under pressure results in a more perfect combustion of the fuel, and under given circumstances of space and time more heat can be generated than under the ordinary mode of construction and operation.

The total expansive effect derived from the combustion minus the heat radiated from the surface of the apparatus is worked through the engine.

Having thus described my invention, What I claim therein as new, and desire to secure by Letters Patent, is

l. In apparatus so constructed as to use the Volatile results of combustion in combination with the steam under equal pressures, the cleanser E, which is distinct from the boiler, and within which the said volatile products are cleansed.

2. In apparatus so constructed as to use the Volatile results of combustion in combination with the steam under equal pressures, the cleanser E, Fig. 1, within which steam is gen erated by the heat of the said Volatile products Which pass through and are cleansed therein.

3. In apparatus so constructed as to use the volatile products ofcombustion in combination with the steam under equal pressures, the generator placed inside of the furnace.

To the above specification of my improvement in furnace and boiler I have signed my hand this 25th day March, 1865.

GEO. I. WASHBURN.

Witnesses:

EDWARD H. KNIGHT, CHARLES D. SMITH. 

